GitHub has open sourced the programme language spec and parser for the Actions workflow tool it announced last year, giving outsiders the opportunity to build their own tools to trigger workflows.

Actions was launched last year, as a way to build, connect and share containers to run a software development workflow on GitHub. Those workflows will be triggered by GitHub platform events like push or release, allowing devs to automate tasks such as the testing and deployment of code to the cloud or the packaging of modules.

A post outlining the move, by GitHub principal engineer, Patrick Reynolds, said the move should expand the tools available for Actions – to date, users have been restricted to GitHub’s offerings.

“We believe there should be programs to check, format, compose, and visualize workflow files,” Reynolds wrote. “We believe that text editors can provide syntax highlighting and autocompletion for Actions workflows.”

But, he continued, “All that can only happen if the Actions community is empowered to build these tools along with us. That can happen better and faster if there is a single language specification and a free parser implementation.”

In fact, said Reynolds, the first project to use the parser is act, a tool for running Actions workflows locally.

Reynolds said that the move to open source would “encourage the Actions community to build tools that generate and manipulate workflow files”, with the spec helping devs understand the language, and not having to develop their own parsers.

The license in question is an MIT license, and Reynolds said there was currently a Go implementation, with a Javascript parser in development.

The workflow language itself a subset of Hashicorp’s HCL, and the parser “builds on top of the open source hashicorp/hcl” parser, Reynolds added.